Downie SR, Katz-Downie DS, Rogers EJ, Zujewski HL, Small E (1998). "Multiple independent losses of the plastid rpoC1 intron in Medicago (Fabaceae) as inferred from phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer sequences". Can J Bot. 76 (5): 791–803. Bibcode:1998CaJB...76..791D. doi:10.1139/b98-047.
Downie SR, Katz-Downie DS, Rogers EJ, Zujewski HL, Small E (1998). "Multiple independent losses of the plastid rpoC1 intron in Medicago (Fabaceae) as inferred from phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer sequences". Can J Bot. 76 (5): 791–803. Bibcode:1998CaJB...76..791D. doi:10.1139/b98-047.